CommitFixture: create a sensible string
CommitFixture: create a sensible string

Stop the crying of the users of `core.autocrlf` everywhere.

libgit2/libgit2sharp,Zoxive/libgit2sharp,Zoxive/libgit2sharp,PKRoma/libgit2sharp,red-gate/libgit2sharp,red-gate/libgit2sharp